Sharpening and edge angle on knife tips

[desmobob]

I just received a new Ontario RAT TAK1 D2.

It was sharp, but not as sharp as I like, so I got out the Sharpmaker and started working on it.

I usually color the bevel with a black magic marker so I can see what's going on when I sharpen and/or reprofile. Using the diamond rods, I could see I was not touching the edge on the swept part of the blade. The bevel angle was really blunt, especially out near the tip and it appears there is no way I'll be able to remove the amount of D2 steel necessary to reprofile it with the sharpmaker.

This TAK1, along with my Swamp Rat Camp Tramp, are my only thick "survival" type blades. The Camp Tramp blade bevel is also high near the tip, but it seems acceptable on that particular knife.

Should I live with that type of blade end angle on the much smaller TAK1, or would it be reasonable to reprofile the blade? (I have a coarse diamond DMT bench stone.)

Also, with a blade that has a changing bevel angle, is hand-sharpening on bench stones the most effective method?

Thanks for any information, insights or tips,
desmobob

 

[gud4u]

It's very common for knives designed for 'rough service' to come with tip grinds less acute than the general edge grind.

I recommend hand-honing the tip with a stone, treating tip-dressing as a discrete task. Using the Sharpmaker will almost certainly result in a rounded tip.

Take your time. Test progress with newsprint-slicing and penetrating tests. If you have difficulty judging angles, use the Sharpie trick to reveal where the stone is cutting.

Hope this helps!

 

[LedSled]

Variable bevel probably means a belt grinder. The closest consumer equivalent is a small belt sander, which has been discussed here before. If that doesn't interest you, check your local yellow pages for barber supply shops. Many of these guys have professional sharpening equipment, and they don't charge a lot. They'll set the bevel as you like, and you can use your Sharpmaker for maintenance.

 

[Bucktool_02]

You can lean the DMT coarse stone onto the sharpmaker rods. It will cut the steel faster, and it's much easier to prevent rounded knife tips. The trick is how to keep it supported up against the sharpmaker rods, some people use rubber bands, I use a block eraser and wedge it in. Also, you have to be careful not to cut yourself because your fingers and hand will no longer be in safe places while using the sharpmaker in this fashion.

 

[DcL]

You can lean the DMT coarse stone onto the sharpmaker rods. It will cut the steel faster, and it's much easier to prevent rounded knife tips. The trick is how to keep it supported up against the sharpmaker rods, some people use rubber bands, I use a block eraser and wedge it in. Also, you have to be careful not to cut yourself because your fingers and hand will no longer be in safe places while using the sharpmaker in this fashion.

That's a great idea but yeah I could see how you might cut yourself either way I'm gonna try that also

 

[desmobob]

You can lean the DMT coarse stone onto the sharpmaker rods.

Simple enough....

I was thinking of making up an angled stand for mine so I could use it vertically, but your idea is easier! But I have a feeling it will take a L-O-N-G time to change the bevel, even with the coarse diamond stone.

I also considered using a file to carefully rough-reprofile that section of the blade, finishing it up with a diamond stone. Any thoughts on that idea?

Thanks very much for all the tips everyone,
desmobob

 

[Alberta Ed]

I've used a fine file to reprofile an edge -- a SRK, specifically -- it worked very well. Turned a not-so-sharp crowbar into a super slicer, with a convex edge.

 

[Dog of War]

Much more stable and safe IMO than propping a stone up on the Sharpmaker rods, you can just hold a benchstone in a vise at the desired angle. I made this jig which makes it a bit handier, but you get the idea:

 

[Bucktool_02]

Just wanted to add: If you have a bench stone holder, you can also use it on the sharpmaker. Just wedge it in with a block eraser. It's a little more stable than just the DMT leaning by itself, since the stone holder is standing on its own two adjustment screws. Again, watch your hand and fingers when using the sharpmaker this way.